Ground testing of an airborne or spaceborne synthetic aperture array radar is generally quite difficult if one attempts to simulate the effects of the orbital environment as well as the Doppler characteristics of the radar echo. In order to accurately simulate the echo, an echo must be produced that realistically models an expected return received by an orbiting sensor. Typical synthetic aperture radar system test apparatus simulate only the Doppler frequency component of a return echo. However, another factor contributing to the frequency characteristics of a return echo is related to the round trip time between the transmission of an outgoing radar pulse and the receipt of an echo or return pulse at the radar transmitter. A conventional simulator only simulates the Doppler component introduced by a predetermined closure rate between the simulated target and the transmitting radar. The additional delay characteristic of the echo return is dependent upon round trip delay time changes as the moving platform passes over the target, these changes being referred to as range curvature information or characteristics. The synthetic aperture radar target simulator provided by the invention accurately simulates a radar echo or return generated by a point target scanned by a synthetic aperture radar and contains effects related both to Doppler frequency information and range curvature information associated with the simulated target.